As is well known in the related art, various types of cameras, each of which includes a number of video cameras housed in one chassis, have been developed for imaging all directions or an entire circumference simultaneously.
In the arrangement of the above-mentioned camera, unless the viewpoint centers of the video cameras coincide with one another, a plurality of images cannot be stitched while maintaining a high quality due to the occurrence of parallax.
Consequently, in order to solve the parallax problem, there have been proposed, for example, an arrangement where viewpoint centers of a plurality of cameras are virtually caused to approximately coincide with one another using a mirror (see Patent Document 1), an optical system capable of eliminating the parallax problem without using a mirror (that is, realizing non-parallax) (see Patent Document 2), and the like.
[Patent Document 1] Japanese Published Patent No. S39-8140
[Patent Document 2] Japanese Unexamined Patent publication No. 2003-162018